20342430721 has 2 divisors, whose sum is σ = 20342430722. Its totient is φ = 20342430720.

The previous prime is 20342430709. The next prime is 20342430763. The reversal of 20342430721 is 12703424302.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20195536321 + 146894400 = 142111^2 + 12120^2 .

It is a cyclic number.

It is not a de Polignac number, because 20342430721 - 2¹⁹ = 20341906433 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20342430721.

It is not a weakly prime, because it can be changed into another prime (20342430421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10171215360 + 10171215361.

It is an arithmetic number, because the mean of its divisors is an integer number (10171215361).

Almost surely, 2^20342430721 is an apocalyptic number.

It is an amenable number.

20342430721 is a deficient number, since it is larger than the sum of its proper divisors (1).

20342430721 is an equidigital number, since it uses as much as digits as its factorization.

20342430721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8064, while the sum is 28.

The spelling of 20342430721 in words is "twenty billion, three hundred forty-two million, four hundred thirty thousand, seven hundred twenty-one".